Acetylene generator



A ril 22, 1958 H. HOOPER 2,331,755

ACETYLENE GENERATOR Filed June 12, 1953 2 Sheets-Sheet 1 FIG. I

INVENTOR HARRY HOOPER ATTORNEY April 22, 1958 H. HooPER ACETYLENE cam-ma 2 Sheets-Sheet 2 Filed June 12, 1953 FIG.

' INVENTOR HARRY HOOPER ATTO RN EY ACETYLENIE GENERATOR Harry Hooper, Westfield, N. 5., assignor to Air Reduction Company, Incorporated, New York, N. Y, a corporation of New York Application June 12, 1953, Serial No. 361,329

4 Claims. (Cl. 48-535) 7 tIols the delivery of calcium carbide from a hopper in the top of the generator to the body of water in the bottom of the generator. The feed valve is usually operated in response to the movement of a diaphragm which is exposed in one side to the pressure of acetylene produced in the generator by the reaction of calcium carbide and water. Frequently the diaphragm is spring-loaded on the side which is opposite to the side exposed to acetylene pressure. With this arrangement the spring serves to push open the feed valve when the pressure of the generated acetylene against the diaphragm is less than a predetermined value, such as 13 p. s. i. g. When the acetylene pressure builds up to about the predetermined value, the force exerted against the diaphragm is sufiicient to overcome completely the spring force and the feed valve is consequently closed. A disadvantage of this arrangement is that a short compression spring is used and, as a consequence, the spring force is not uniform during compression and expansion of the spring with the result that desired feed of carbide, to generate the desired quantity of acetylene at the desired pressure, is not maintained during the generation cycle and excessive pressure variations result. Another undesirable feature of this arrangement is that the spring force can be tampered with since it is on the side of the diaphragm exposed to the atmosphere and hence accessible for adjustment. With the compression spring construction this adjustment feature is desirable in order to vary the generator acetylene pressure and subsequently to compensate for variations which occur due to use. However, sometimes the pressure is set above the permissible limit without authority and a dangerous condition results or else the acetylene at excess pressure is vented.

It is the primary object of this invention to provide an improved carbide feed mechanism which is capable of supplying acetylene at uniform pressure during varying demands.

. It is a further object to provide an improved, adjustable carbide feed mechanism which cannot be operated above a predetermined pressure.

A further object is the provision of an improved adjustable carbide feed mechanism in which the adjustable means are not easily accessible.

An additional object is the provision of an improved, adjustable, sensitive carbide feed mechanism which does not require close dimentional tolerances.

, -A further object is the provision of an improved carbide mechanisrn having combined therein adjustable cooperating structure which prevents operation in excess of a predetermined pressure value and prevents operation tates Patent According to disclosed preferred embodiment of the invention, the carbide feed element which controls the delivery of carbide from the feed hopper to the water in the generator is diaphragm-actuated by acetylene pressure to stop feeding carbide and the force opposing the acetylene pressure is provided by an inaccessible, adjustable spring device which is rendered inoperative, if a predetermined spring force is exceeded, by structure which includes a limited buoyant float. With this arrangement the adjustable spring cannot be adjusted to exceed a predetermined force with the result that acetylene cannot be generated at pressures in excess of a predetermined pressure, such as 15 p. s. i. g.

The above and other objects, along with the features and advantages of the invention, will be better understood by reference to the following description and the accompanying drawing in which:

Fig. 1 is a vertical section through the hopper and carbide feed mechanism of an acetylene generator embodying the invention, with a few of the parts being shown in side elevation and shows the feed mechanism in the no-feed position when operation above the predetermined pressure has been attempted and;

Fig. 2 is an enlarged, broken cross-sectional view of the elements of the carbide feed mechanism which shows the generator in the feeding position during a normal generation period.

Referring to Fig. l of the drawing, it can be seen that the carbide hopper of a carbide-to-water type acetylene generator is identified by reference numeral 10. The carbide which is charged into the hopper it is usually in the form of small particles, as is well understood in the art. The hopper has a downwardly sloping bottom 12 at the center of which is a discharge opening 14. Carbide in the hopper is free to move downwardly through the opening 14 into a cylindrical spout 116 from which it passes through an opening 18 at the bottom of the spout onto a feed plate or feed valve 20, having a conical upper surface. A ring 22 extends downwardly from the spout 16 and encircles its discharge opening 18 The ring 22 supports a flexible valve lip 24 having a serrated lower edge which bears against the upper conical surface of the feed plate 20 and functions as a valve seat in the manner set forth in U. S. Patent No. 2,480,292 (issued to the instant inventor on August 30, 1949) to assure that no carbide passes by the feed plate 20 when it is closed.

When the feed valve 29 is opened, carbide is discharged from the spout 16 onto the upper conical surface of the feed valve and then into the water 26 in the generating chamber 27 of the generator where the carbide reacts with the water to form acetylene.

- The hopper 10 is charged with carbide through an opening provided at the top of the hopper which is sealed by a cover plate 30 removably held in place by a yoke 32 and clamping screw 34. A vent or pressure relief valve (not shown) is provided as is conventional.

The feed valve 20 is secured to a verticallyextending valve rod 40 which extends upwardly into a casing 42. The casing is supported in the feed hopper 10 by horizontal pipes 44 and 46 which are attached to the vertical wall of the hopper It). The lower end of the easing is closed by a diaphragm 48 which is clamped at its periphery to the casing in a gas-tight manner by a clamping ring 49. The valve rod 4% is attached to the diaphragm by suitable means 50 so that the movement of the diaphragm upwardly is transmitted to the valve rod 40 and hence to the feed valve 20.

The under side of the diaphragm 48 is acted upon by the pressure of the acetylene produced in the generator by means of pipe 51 which extends vertically from the generating chamber 27, through the bottom 12 of the hopper, to the top portion of the hopper 10. The space within the casing 42 is vented to the atmosphere by pipe 44 so this space above the diaphragm is always at atmospheric pressure. With this arrangement, the diaphragm has equal forces acting on its two faces at the beginning of a generating cycle immediately after charging with carbide. Thereafter, the generation of acetylene will exert a pressure which is above atmospheric on the underside of the diaphragm 48 which would tend to raise the feed valve 2 3 to closed position except for an opposing force clue to a spring-float arrangement to be described hereinafter.

When the generator is not in operation or is being recharged, the feed valve 29 is held in its raised or closed position by means of a cam 52 which acts against the lower face of plate 54 attached to the upper part of valve rod 4d. The cam 52 is secured to the inner end of a shaft 56 which is journalled to rotate in the pipe 46 and which extends to a point outside of the hopper where it is connected to a handle 58. When it is desired to start the generation of acetylene, the handle 58 is partially rotated to turn the cam 52 to a new position which will allow the valve rod 49 to move downwardly and open the feed valve 2%. At the full open position of the feed valve 21 when starting up, an excessive flow of carbide from the feed hopper into the water in the generator is prevented by a disc 59 on the valve rod which then closes the opening 14 in the bottom of the hopper. The need for restricting the flow of carbide from the hopper by means of the disc 59 exists only at the start of acetylene generation when no gas pressure exists in the generator. As soon as the valve rod has been lowered by turning the handle 58, carbide falls rapidly into the generating chamber 27 since there is no acetylene pressure acting on the diaphragm tending to raise it and therefore the feed valve 20 is at its lowest position. If it were not for the disc 59, by the time the feed valve 20 is eventually raised by the acetylene pressure on the diaphragm 48 an excessive amount of carbide would have been fed to the generating chamber 27 causing a further rise in pressure of the acetylene or a so-called after generation which is undesirable because of the possibility of wasting gas through a conventional generator relief valve (not shown). The disc 59 causes the carbide to be delivered to the generating chamber 27 in an amount which is no greater than the amount that can be retained in the spout 16 below the opening 1 of the hopper. This construction and mode of operation is set forth in detail in the U. S. Patent No. 2,519,471 (issued to the instant inventor on August 22, 1950).

The larger-dia-metered, hollow portion or tube 60 of the valve rod 4%, below the valve plate 20 to which tube 60 is attached at its upper end, contains a spring 61 which is attached to the bottom of valve plate 20 and the upper hooked end of shackle 62 which extends into the bottom portion of cylindrical tube 60 of valve rod 40. The shackle 62 has threaded thereon a horizontally extending flange or plate 64 which is held in position by nut 66. The upper surface of flange 64 is shown abutting the lower edge of cylindrical tube 60. This relation, as shown, exists when someone has attempted to operate the generator at a pressure above the predetermined, permissible pressure by extending spring 61, as will be explained in detail hereinafter. When the foregoing condition exists, the interconnected structure between the pivot connection 76 and the diaphragm 48 in eifect becomes a rigid member of fixed vertical height which structure is urged upwardly .by the rotated float 84, acting through lever 78. In this state and due to the proper arrangement among the arms of the lever and the buoyant force of the float, it is impossible to generate acetylene at a pressure in excess of the prede: termined, permissible value since the value of float-lever downward force is such as to maintain the feed valve open only when the force on the diaphragm is derived 2,831,765 A I H g V I 7 r 4 from an acetylene pressure of less than the predetermined, permissible amount. Thus, when the force on the diaphragm is due to acetylene at 15 p. s. i. g. for instance the opposing force due to the float is insufiicicnt to hold the feed valve open. Under the foregoing circumstances, the instant generator operates in a manner which is similar to operation of the acetylene generator in U. S. Patent No. 2,519,471 (issued to the instant inventor on August 22, 1950), reference to which may be had for further details as to construction and mode of operation.

The bottom of the turnbuckle 68 has a lower rod 72 threaded vertically therethrough and locked in position by a nut 74. The lowermost end of the rod 72 is pivoted at 75 to a lever 78 which is fulcrumed at 80 by means of ueort 82. Support 82 is attached to an L-shaped bras... 3 which. has its short leg extending to the left from support 32 and has the top of the vertical leg attached to the inclined bottom 12 of the hopper 10. With this arrangement, the removal of the hopper 10 from the edge of the top opening of the generating chamber 27 also includes the removal of the float 84 and associated structure, except for stop so which is attached to the wall of the chamber 27 and is avoided by lateral movement of the hopper assembly. The other end of the lever 73 carries a float 84 which will be restrained from counterclockwise, upward movement by stop 86 during normal operation which operation is illustrated in Fig.2.

Referring now to Fig. 2 which discloses the instant generator when it is feeding carbide in a normal manner and has not been tampered with in an eifort to generate acetylene at pressures above the predetermined, permissible value, it can be observed that the float 84 abuts the stop 86 which is below the level 88 of the water in generating chamber. This water level 88 is always maintained during normal operations by well-known means. However, in the event that this level 38 of water is not maintained, it is apparent that the float 84 will descend clockwise with the water level, urge the flange against the lower edge of tube 69 and hence close the feed valve 2%). In this manner, the dangers involved in generating acetylene with an insuflicient quantity of water is avoided. v

It is to be noted that in the operative position shown since the flange 64 does not abut the lower edge of tube 60, the long tension spring 61 is the efiective force op' posing the diaphragm 48. The float 84 would normally assume a position higher than that to which it is limited by stop 86 and so for normal operation the pivot connection 76 is rigid. Only when it is attempted togen crate acetylene at pressures which are not permissible, for instance above 15 p. s. i. g., by extending spring'fil by means of turnbuckle 68 will the flange 64 abut the lower edge of tube 60 due to the lowering of the float as shown in Fig. 1 and thus eliminate the etfect of the spring, assuming there is an adequate supply of water. This will occur because maximum downward force due to the lever and float is less than or equal to the force which acetylene at 15 p. s. i. g., for example, will exert on the diaphragm.

It is to be appreciated that, in the Fig. 2 showing of the normal operating arrangement, the lever-float structure constitutes, in efiect, a rigid anchor for the turnbuckle-spring structure. With this normal operating condition when the generation of acetylene is occurring at a pressure below the predetermined, permissible value, it is apparent that the long tension spring having a low spring rate is the effective force which opposes the force due to acetylene acting upon the underside of the diaphragm 48 and tends to open feed valve 20. By means of turnbuckle 68 and associated structure, it is possible to vary the pressure at which acetylene is generated as long as it is below the predetermined, permissible value. It is to be noted that this adjustable tension spring atrangement permits manufacture of parts without hold ing them to close tolerances in order to get a generator which will operate below a predetermined pressure.

The mode of operation of the instant generator is believed to be apparent to one skilled in the art from the foregoing description. However, in order to point out certain salient features, the normal or regular operation and the operation which occurs when the water level gets dangerously low or when an operator or other person attempts to generate acetylene at a pressure which exceeds the permissible value, will be briefly described.

Assuming the generator has been adjusted at the place of use or at the factory by qualified personnel to generate acetylene at 13 p. s. i. g. and that, after the acetylene has been withdrawn and delivered, for instance, to welding torches through pipelines and hoses to the extent that the pressure in the generating chamber is below 13 p. s. i. g., the instant generator will be operating with the structural positioning shown in Fig. 2. Thus, carbide will be fed past feed plate 20 and dropped into water 26. The acetylene which is generated will increase the pressure until the upward force which it exerts on diaphragm 48 overcomes the downward pull of the long tension spring 61. This results in the closing of the feed valve 20 and interrupts the feeding of carbide. When the acetylene pressure drops below 13 p. s. i. g., the spring 61 will again pull open the valve 20 and carbide will be fed until the pressure again increases to 13 p. s. i. g.

During this normal or regular operation when the generator is supplying acetylene to torches, for instance, in varying amounts, the feed valve 20 will move open and closed almost continuously in response to the opposing pulling forces of the diaphragm 48 and the spring 61. The long tension spring 61 having a low spring rate permits slight pressure increases to close the valve; and, for the same reason upon slight pressure decreases, the long spring permits the feed valve to open. The foregoing sensitivity permits good pressure regulation and tends to minimize after-generation pressure rises.

It is to be noted that the desired, permissible operating pressure can be set without requiring exact dimensional tolerances in fabricating since the spring is adjustable by means of turnbuckle 68 and that the sensitivity of the carbide feed mechanism is further improved by providing a long tension spring, rather than a compression spring, because frictional forces caused by side thrust of guiding parts usually encountered are eliminated.

In case of the remote event when the supply of water in generating chamber 27 decreases below the level of the normal position of the float 84, the float will rotate clockwise or descend and urge the flange 64 against the lower edge of tube 60. This operation will render spring 61 inoperative so that it cannot urge the valve 20 to an open position and will result in valve 20 being closed. In this manner, the remote but very dangerous contingency of generating acetylene with an insuflicient quantity of water is prevented in a generator having carbide feed mechanism which has a sensitive, inaccessible, adjustable diaphragm-loading mechanism.

If an operator or some other person attempts to 0p erate the generator with the acetylene pressure exceeding the values prescribed by fire underwriters or other safety agencies, he is first faced with the difficulty of gaining access to the adjusting mechanism or turnbuckle 68. This in itself greatly tends to discourage tampering since the turnbuckle 68 would be easily accessible only if the entire feeding mechanism including hopper is lifted off from the generator chamber 27. In any event and assuming such tampering with has occurred, the genertion of acetylene at pressures in excess of a predetermined permissible pressure will not be possible. The builder, by arranging the arms of lever 78 and the buoyant force of float 84, can set this predetermined permissible pressure in the manner set forth in the aforementioned Patent No. 2,519,471. Thus, if it is attempted to tension the long spring 61 in such a manner that its force exceeds the force which acetylene at the predetermined, permissible pressure will exert on diaphragm, the lower support or anchor for spring 61 including float 84 and lever 78 will cease to be rigid; and, after the float 84 descends or moves away from stop 86, the connection between pivot 76 and valve 20 will become, in effect, integral. With this operation, the total downward force at pivot 76 (due to the buoyant force of float 84) will be a force which effects the opening of valve 20 only when the force of the acetylene against diaphragm 48 is less than that created by acetylene at the predetermined permissible pressure.

The advantage in using a long tension spring resides in the fact that during normal operation the spring will produce a loading force on the diaphragm which remains substantially uniform throughout the displacement of the carbide feed valve due to the rate of the spring.

It is to be noted that with the construction herein disclosed the desired pressure setting can be made during assembly and thereafter cannot be easily tampered with.

An outstanding feature of the instant invention is the arrangement of the connection between the float and feed valve so that the buoyant force of the float determines the maximum pressure at which the generator can function.

From the foregoing it is believed apparent that a simple, easily-constructed, tamper-proof carbide feed mechanism has been provided which gives the proper feed as the pressure of the generated acetylene varies. It is also to be appreciated that the diaphragm loading force can be adjusted in a range below a predetermined force due to acetylene gas pressure but that, when an operating acetylene pressure above the value which will give the predetermined force is attempted, the adjustable spring arrangement becomes inoperative and the buoyant force of the float (equivalent to the maximum permissible force exerted by acetylene in the diaphragm) becomes the sole force urging the feed valve to open position;

It is to be understood that various modifications and changes can be made in the invention as herein specifically disclosed by one skilled in the art without departing from the invention as defined in the following claims.

I claim:

1. An acetylene generator having a carbide feed valve for feeding carbide into the water in the generating chamber and means for pulling the valve upwardly to closed position in response to generated acetylene and further having combined therewith a long tension spring arranged to pull said valve downwardly to open position, said spring having an adjusting mechanism, said spring being normally anchored by one end of a pivoted lever, awater float connected to the other end of said pivoted lever and arranged to be submerged in the water in said generating chamber, and said lever and float being so constructed and arranged as to exert a force which is less than the force which acetylene, at a predetermined pressure, will exert on said means for pulling the valve upwardly in response to generated acetylene whereby acetylene cannot be generated in excess of said predetermined pressure, said spring being encased in a hollow tube, and said connection between said spring and said lever including an element positioned adjacent to the bottom of said tube and adapted to abut the bottom thereof when said float is lowered whereby said carbide valve is closed when the level of the water in said generating chamber is below a predetermined level.

2. In a carbide-to-water acetylene generator, a carbide feed mechanism comprising a carbide hopper having a discharge opening in its lower portion, a vertically movable feed valve controlling said discharge opening and hence the delivery of carbide from the hopper to the water in the generator, a diaphragm exposed at one side to the pressure of the acetylene produced in the generator so that such pressure tends to produce movement of the diaphragm in one direction, structural connections between the diaphragm and the feed valve for positively lifting the valve to closed position when the 'diaphragm is moved by the acetylene pressure in said direction, a rigid and hollow member connected to said feed valve and extending vertically downwardly from said valve, a spring encased in said hollow member, said spring being operatively connected to said feed valve to pro duce a downward pull which tends to lower the feed valve to open position and is transmitted to the diaphragm so that it tends to move the diaphragm in a direction opposite to that in which the acetylene pressure tends to move it, a lighter-than-water float so positioned as normally to be completely submerged in the body of water in the generator and operatively arranged and connected to said spring by structural connections so that the float causes a downward pull to be exerted on sm'd spring, said connections including a member directly connected with said spring and relatively movable longitudinally with respect to said rigid member-to adjust the tension on the spring, said member connected with said spring carrying an element positioned adjacent the bottom of said rigid member and adapted to abut the bottom thereof, Whereby, when it is attempted to adjust the tension in said spring to a value greater than the force exerted by said float, said float is displaced and such adjustment is ineffective.

3. An acetylene generator having a carbide feed valve operable to admit controlled amounts of calcium carbide into a quantity of water, a spring in tension urging said valve to open position, a diaphragm responsive to generated acetylene pressure urging said valve to a closed position in opposition to the force exerted on said valve by said spring, a rigid and hollow member connected to said feed valve and extending vertically downwardly from said valve, said spring being encased in said hollow memher, and a yieldable anchor for said spring, said yieldable anchor comprising a lever and a float positioned to be immersed in said quantity of water and structural connections between said spring and lever including means directly connected with said spring and relatively movable longitudinally with respect to said rigid member for adjusting the closing tension exerted by said spring on the carbide feed valve, thereby to vary the generated acetylene pressure required to overcome the spring tension, said last-mentioned means forming part of a turnbuckle and carrying an element positioned adjacent the bottom of said member and adapted to abut the bottom thereof, whereby excessive spring pressure overcomes the buoyancy of said float to displace said float and relieve the tension in said spring to prevent the development of excessive pressure of generated acetylene.

4. In a carbide-to-water type acetylene generator having a carbide feed valve which closes in response to acetylene pressure to prevent feeding of carbide to water in the generator, a diaphragm, means connected to the diaphragm for pulling said valve upwardly to closing position in response to generated acetylene pressure, a tension spring connected at one end to said valve, a rigid and hollow member connected to said feed valve and extending vertically downwardly from said feed valve, said spring being encased in said hollow member, and a yieldable anchor for said spring and opposing the force of the acetylene on the diaphragm and limiting the pressure of generated acetylene to a predetermined value, said yieldable anchor comprising tension adjusting mechanism having one end thereof secured to the other end of the spring, a water lioat positioned normally to be completely submerged in the water in the generating chamber and a pivoted lever, one end of the pivoted lever having said float connected thereto and the other end of said lever being connected to the other end of said tension adjusting mechanism and an element carried by said adjusting mechanism positioned adjacent the bottom of said rigid member and adapted to abut the bottom thereof, whereby said spring is rendered inoperative when the quantity of water in said chamber is less than a predetermined quantity or when the tension in said spring is adjusted to exceed a predetermined value.

References Cited in the file of this patent UNITED STATES PATENTS 1,202,872 Michael Oct. 31, 1916 2,106,972 De Motte Feb. 1, 1938 2,188,278 De Motte Jan. 23, 1940 2,202,848 Geiger June 4, 1940 2,255,536 Smith Sept. 9, 1941 2,385,087 La Force Sept. 18, 1945 2,480,292 Hooper Aug. 30, 1949 2,519,471 Hooper Aug. 22, 1950 FOREIGN PATENTS 19,414 Sweden May 27, 1905 

1. AN ACETYLENE GENERATOR HAVING A CARBIDE FEED VALVE FOR FEEDING CARBIDE INTO THE WATER IN THE GENERATING CHAMBER AND MEANS FOR PULLING THE VALVE UPWARDLY TO CLOSED POSITION IN RESPONSE TO GENERATED ACETYLENE AND FURTHER HAVING COMBINED THEREWITH A LONG TENSION SPRING ARRANGED TO PULL SAID VALVE DOWNWARDLY TO OPEN POSITION, SAID SPRING HAVING AN ADJUSTING MECHANISM, SAID SPRING BEING NORMALLY ANCHORED BY ONE END OF A PIVOTED LEVER, A WATER FLAT CONNECTED TO THE OTHER END OF SAID PIVOTED LEVER AND ARRANGED TO BE SUBMERGED IN THE WATER IN SAID GENERATING CHAMBER, AND SAID LEVER AND FLOAT BEING SO CONSTRUCTED AND ARRANGED AS TO EXERT A FORCE WHICH IS LESS THAN THE FORCE WHICH ACETYLENE, AT A PREDETERMINED PRESSURE, WILL EXERT ON SAID MEANS FOR PULLING THE VALVE UPWARDLY IN RESPONSE TO GENERATED ACETYLENE WHEREBY ACETYLENE CANNOT BE GENERATED IN EXCESS OF SAID PREDETERMINED PRESSURE, SAID SPRING BEING ENCASED IN A HOLLOW TUBE, AND SAID CONNECTION BETWEEN SAID SPRING AND SAID LEVER 